1. Field of the Invention
The present invention relates generally to a steering wheel and more specifically to a steering wheel construction via which the steering wheel and the steering shaft can be connected.
2. Description of the Prior Art
In order to connect the central boss of a steering wheel to a steering shaft, it is a common practise to form corresponding serrated and a tapered sections on the steering shaft and in the central boss and to use a nut and spring washer or plate spring to secure the two components together. The number of serrations which are formed usually numbers in the range of 36 to 40.
As a result of the meshing of the serrations, in the case wherein the positioning of the hub on the shaft is off by one serration, the positioning of the steering wheel is changed by 9.degree.-10.degree.. In the event that happens, it is necessary to remove the wheel from the steering shaft, rotate it to a position in which the required meshing takes place, and again slide the hub into position on the serrated section. This of course tends to increase the amount of work necessary to suitably complete the assembly of the unit.
However, even when the boss is correctly located on the steering shaft and the appropriate serrations are in engagement, still, in the event that the connection at the lower end of the steering shaft is not exactly correct and some positioning error is present, the positioning of the steering wheel can be off by an amount which is approximately half of a serration (e.g., about 5.degree.). In this case, repositioning of the hub on the steering shaft is of no avail and only shifts the position of the offset.
In view of the above, it has been proposed in JP-A-61-241262 to use a plurality of stopper pieces and to adjust the steering wheel angle in a manner which compensates for small offsets. However, with this technique, it is necessary to use a plurality of stopper pieces and requires that the steering shaft be formed with a particular type of configuration. Accordingly, the use of the usual serrations and tapers is rendered impossible.
A further proposal for overcoming the above mentioned problem is disclosed in JP-A-63-263166. In this arrangement, a bush is disposed between the steering shaft and the boss of the steering wheel. This arrangement rendered the angle between the steering shaft and the bush and the angle between the bush and the steering wheel boss separately adjustable with the intention of rendering small angular offsets correctable. However, this technique firstly requires refitting between the bush and the hub. This of course increases the number of operations which are required to achieve the appropriate steering wheel positioning and results in a lot of troublesome time consuming work.